Solvatochromism of β-Naphthol

Solntsev, Kyril M.; Huppert, Dan; Agmon, Noam

doi:10.1021/jp982333c

Cited by 104 publications

(129 citation statements)

References 53 publications

Supporting

Mentioning

112

Contrasting

Order By: Relevance

“…These results are accountable by our previous studies of the solvatochromic shift of photoacid as measured in various solvents. [49][50][51] For the ROH* emission band, the blue shift indicates a decrease of the solvent polarity and of the hydrogen bonding accepting power (with respect to water) of the solvent. The red shift of RO -* implies that the water molecules in the immediate vicinity of the excited pyranine are a poorer hydrogen-bond donor.…”

Section: Resultsmentioning

confidence: 99%

Proton Antenna Effect of the γ-Cyclodextrin Outer Surface, Measured by Excited State Proton Transfer

et al. 2006

Self Cite

View full text Add to dashboard Cite

The reversible proton dissociation and geminate recombination of the common photoacid, 8-hydroxypyrene-1,3,6-trisulfonate (pyranine), either in dilute aqueous solution or when forming a complex with gamma-cyclodextrin (gamma-CD), has been studied by time-resolved fluorescence spectroscopy and supplemented by molecular modeling and dynamics simulations. We find that the dissociation rate of the proton from the excited molecule was decreased to about approximately 50% of its value in water, while the rate of recombination was doubled. These observations were evaluated by molecular modeling of the reactants at atomic resolution. The combination of the two methodologies indicates that the pyranine in the complex can assume more than one level of interaction with the solvent. The polysugar torus surrounding the pyranine perturbs the hydrogen bond in the dye's immediate vicinity and deforms the electrostatic potential inside the Coulomb cage, causing major deviations from a simple spheric symmetry. These observations can account for the special kinetic features measured for the complex. We suggest that this system can be used as a basic model for evaluating the mechanism of proton transfer in non-homogeneous systems, such as the surface of proteins or biomembranes.

show abstract

Section: Resultsmentioning

confidence: 99%

Proton Antenna Effect of the γ-Cyclodextrin Outer Surface, Measured by Excited State Proton Transfer

et al. 2006

Self Cite

View full text Add to dashboard Cite

show abstract

“…Our interpretation of R is corroborated by the observation that the a i values for 2OH are similar to those of 5CN2OH. 48 Thus, either the cyano group is not a good HB acceptor or else its strength is independent of the excitation state.…”

Section: Discussionmentioning

confidence: 99%

Photochemistry of “Super”-Photoacids. Solvent Effects

1999

Self Cite

View full text Add to dashboard Cite

We study steady-state and time-resolved fluorescence of 5-cyano-2-naphthol in various pure solvents. To some of these, excited-state proton transfer occurs within the excited-state lifetime of the chromophore. Solvatochromic shifts in the acid and anion bands are analyzed using the empirical Kamlet-Taft approach. The hydrogen-bond donated from the OH group to basic solvents accounts for most of the shift in the excitation spectra. This bond produces considerably larger shifts in the emission spectra, suggesting that it strengthens in the excited state. In contrast, the hydrogen bond donated from protic solvents to the hydroxyl oxygen is cleaved following photoexcitation. This bond (and not the change in dielectric constant) is responsible for the solvent-induced blue shift in anion fluorescence. Hence it must re-form simultaneously with the protontransfer event. Our time-resolved fluorescence data fit the solution of the Debye-Smoluchowski equation for reversible geminate recombination in a field of force, provided that the difference in excited-state lifetimes and contact quenching are taken into account. An extended theory of reversible geminate recombination provides an accurate description of the asymptotic behavior in this case. The quenching processes correlate with the solvent hydrogen-bond donation ability, implicating the involvement of hydrogen-bonded pathways.

show abstract

“…The solvatochromic effects of synthesized dyes are shown in Table 4. It is clear that all synthesized dyes except 10 exhibit positive solvatochromism in accordance with most chromogens so that the absorption bands of dyes move towards longer wavelengths as the polarity of the solvent increases [19]. As observed in dyes 7ae7f, going from the DMSO to DMF causes only a maximum of 4 nm change in the absorption maxima of the dyes.…”

Section: Solvatochromic Effectsmentioning

confidence: 68%